DE112012002578T5 - Pyrolysis of biomass in the production of biofuels - Google Patents

Abstract

Manufacture of a biofuel from a raw material that includes a solid biomass material such as Lemna. Aquatic plants, such as pre-processed Lemna or whole Lemna, serve as a rich source of lipids, carbohydrates, protein residues, cellulose and other organic materials that have the potential to be converted to hydrocarbons. A hydrocarbon feedstock is fed to the coking process and the reaction products generated in the heating process are collected. A coke product has an isotropic structure.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of 35 U.S.C. Section 119 (e) of U.S. Provisional Application Serial No. 61 / 500,250, filed Jun. 23, 20111, which is incorporated herein by reference in its entirety, that is, as fully set forth herein.

FIELD OF THE INVENTION

The invention relates to the production of a biofuel composition from a raw material including a solid biomass material.

BACKGROUND OF THE INVENTION

Rising costs and impending shortages and supply disruptions have recently highlighted the need for fuel sources as an alternative to petroleum-based products.

The present invention presents a process for producing biofuels in a refinery heat processing unit by co-processing biomass along with distillates and residues from a traditional refining process.

In connection with the production of fuels from a variety of renewable resources, there are problems, namely, to achieve the desired properties of a particular fuel. Accordingly, a process is desired wherein renewable resources can be effectively used to produce high quality fuels.

SUMMARY OF THE INVENTION

The process of producing biofuel by retarded coking of a raw material, according to one embodiment of the invention, involves co-processing a solid biomass with the fresh hydrocarbon feed in a conventional delayed coking unit.

In one embodiment of the claimed invention, the raw material of the conventional delayed coking unit comprises a hydrocarbon feed such as petroleum residues with or without distillates and a solid biomass material. In certain embodiments of the invention, the biomass material is derived from aquatic plants. For example, aquatic plants such as pre-processed or whole lemna serve as a rich source of lipids, carbohydrates, protein residues, cellulose and other organic materials that have the potential to be converted to hydrocarbons. Preliminary processing of Lemna involves extraction of a high protein stream prior to biomass conversion in a coker. Other sources of solid biomass material that may be used in embodiments of the invention include materials of plant origin such as sour grass, woody materials, oilseeds, and animal derived materials such as fats. In the embodiments of the invention, biomasses of various kinds and origins can be used.

In certain embodiments of the invention, the solid biomass is mixed in varying proportions with hydrocarbon residue, and the resulting slurry is coked in a delayed coker. The slurry may be formed in the fresh feed section of the unit or in the coke drum during the reaction stage. The volume percentage of the amount of solid biomass in the slurry may be increased depending on the capacity of the coker unit and its ability to handle the biomass material.

BRIEF DESCRIPTION OF THE DRAWINGS

1 shows a schematic diagram of a delayed coking process; and

2 FIG. 10 shows a flowchart of a method for processing biomass according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

In one embodiment of the invention, a delayed coking process with a slurry comprising hydrocarbons and a solid biomass material in a delayed coker, as in US Pat 1 or another suitable refinery heat processing unit, e.g. As a visbreaking unit or a thermal cracking unit performed.

In one embodiment of the invention, the coking process is fed with a hydrocarbon feed through the liquid reservoir at the bottom of a coker fractionator. The fractionator serves as the point at which various liquid and gaseous products are withdrawn, for example, fuel gas and LPG, light naphtha, heavy naphtha, light gas oil, medium gas oil and heavy gas oil. The bottom product from the coker fractionator is fed to a coker heater so that the thermal cracking reactions can start. The effluent from the coker heater is then transferred to a coke drum where the reactions of thermal cracking and coking or carbonation are exhausted and produce coke and a light hydrocarbon effluent from the coke drum (coke vapor) leading to the coker breeze. Fractionator is passed on. In certain embodiments, a portion of the condensed liquids may be recycled and pumped with the feed material into the coker heater.

In one embodiment of the invention, the solid biomass material is mixed with a hydrocarbon residue feed and fed to the coker fractionator.

In another embodiment of the invention, solid biomass material may be added directly during the reaction or quenching stage of the coke drum.

In another embodiment of the invention, solid biomass material, preferably in slurried form, may be added, with prior heating, directly to the coker heater feed line or directly to the coke drum. In other embodiments of the invention, the solid biomass material may be supplied to the feed of the coker heater without prior heating.

The slurried biomass may be gradually heated and heated rapidly after being heated at low temperature to reduce charring with generated water and acid hydrocarbons otherwise present in the main section of the Koker fractionator, in the coker heater, in the coke drums, the fractionator Recovery systems and refinery waste systems.

The weight percentage of the amount of solid biomass material relative to the remainder of the slurry ranges from 0.1% to 60%. In one embodiment of the invention, a preferred weight of the amount of solid biomass relative to the remainder of the slurry ranges from 10% to 40%. In another embodiment of the invention, a preferred weight of the amount of solid biomass relative to the remainder of the slurry ranges from 20% to 40%. The amount of biomass in the slurry may vary depending on the capacity of the Koker unit. A low capacity unit may be capable of receiving between 5 and 20% by weight of biomass in petroleum residue, whereas a high capacity unit may be capable of between 40 and 50% by weight of solid biomass material in the petroleum residue Process slurry.

As biomass in the range of 0.1% to 60% is introduced into the coker influx, coking is carried out at normal temperatures and pressures. In a delayed Koker the heavy oil supply, z. For example, the vacuum residue is pumped to the coker heater at a pressure of about and preferably 300 to 4000 kPa (slightly 44 to 580 psig) where it is heated to a temperature of about 460 ° C to 530 ° C. It is then discharged into the coke drum, where a lower pressure prevails to allow the volatiles to be removed overhead, typically from about 65 to 1100 kPa (about 10 to 58 psig) and preferably in the range of 100 to 300 kPa (about 10 to about 30 psig) 160 psig). Typical operating temperatures of the upper drum portion are between about 405 ° C and 460 ° C.

An embodiment of the method of the invention is in 2 shown. The flowchart in 2 describes a process for the pyrolysis of biomass. In one step of the described method, a raw material containing biomass is provided (step 102 ). In a subsequent step (step 104 ) the raw material is subjected to heat processing. In certain embodiments of the invention, the heat processing is performed using a delayed coking process (step 106 ) carried out. In other embodiments of the invention, the heat processing is carried out using a fluidized bed coking process (step 108 ) carried out.

If the delayed coking process is used (step 106 ), in some embodiments, the feed is heated at a pressure of 300 to 4000 kPa to a temperature of 460 to 530 ° C, after which the heated stream at a pressure of 65 to 1100 kPa and a head temperature of 405 to 460 ° C in the delayed coke drum is unloaded.

When the fluidized bed coking process in the heat processing step (step 108 ) is used, the feed is discharged at a pressure of atmospheric to 400 kPa and a temperature of 480 to 565 ° C in a fluidized bed coking reactor.

Typically, the solid biomass begins to decompose at temperatures as low as 200 ° C. However, the stability of the solid biomass is not affected during the pyrolysis process, since the main reactions take place in the coke drum and are endothermic.

In one embodiment of the invention, the low temperature biomass decomposition reactions produce water of reaction and a number of potentially valuable chemical species, including acetic acid.

The biomass decomposition reactions in the delayed coker affect the total reaction mass at high temperatures in the coke drum. The submitted reaction material must be at a temperature high enough to overcome the biomass endothermic decomposition reaction. This temperature is significantly higher than would be required in a conventional coker and is dependent on the amount of biomass in the feed mixture. This has an impact not only on operation, but also on the specification of the heat transfer equipment, typically a fired heater, to deliver higher than normal enthalpy.

• a. Entfernung einer signifikanten Menge an Reaktionswassser aus dem Kokerbetrieb, was das Verarbeiten der resultierenden Produkte vereinfacht.
• b. Es verringert den Einfluss der gesamten Enthalpievarianz im Vergleich zu Nichtbiomasse-Betrieben, die in dem Koker erforderlich ist.
• c. Entfernung und Gewinnung von wasserlöslichen Säure-Komponenten für den Koker. Die Komponenten könnten getrennt gewonnen werden, sollten sie sich als kommerziell attraktiv erweisen.
• d. Die Segregation des Säure-Wassers von den anderen Koker-Wasserströmen vereinfacht Korrosion und Behandlung der normalen Wasserströme in und aus dem verzögerten Koker.
• e. Das Vorreaktionssystem kann auf eine Anzahl von verschiedenen Wegen konfiguriert werden. Einige von diesen sind folgende:
• (1) Aufschlämmung mit heißem Erdöl-Rückstand und Abziehen des Wassers und der leichten Bestandteile unter Verwendung eines einfachen Gefäßes; und (2) Aufschlämmung mit heißem Erdölrückstand und Abziehen des Wassers und der leichten Bestandteile in einem Turmsystem.

One embodiment of the invention relates to an alternative configuration for co-processing biomass in a delayed coker, wherein a pre-reaction section lies either inside or outside the coker. The use of the pre-reaction section, either inside or outside the coker, would have the following advantages:

• a. Removal of a significant amount of water of reaction from the coker operation, which simplifies the processing of the resulting products.
• b. It reduces the influence of total enthalpy variance compared to non-biomass operations required in the coker.
• c. Removal and recovery of water-soluble acid components for the coker. The components could be recovered separately should they prove commercially attractive.
• d. The segregation of acid water from the other coker water streams facilitates corrosion and treatment of the normal water flows in and out of the delayed coker.
• e. The pre-reaction system can be configured in a number of different ways. Some of these are the following:
• (1) Slurry with hot petroleum residue and remove the water and light components using a simple vessel; and (2) slurry with hot petroleum residue and stripping off the water and light components in a tower system.

WORKING EXAMPLES

The present invention will be more readily understood and appreciated by reference to the examples presented below. However, these examples are only to be considered representative of the scope of the present invention and by no means limit the invention.

The dried lemna biomass used as solid biomass material in certain embodiments of the invention has the following composition (in weight%), as in U.S.P. Table 1, which may vary depending on growth optimization and pre-processing level following protein extraction. Table 1 minerals carbon hydrogen nitrogen sulfur oxygen 6.95 45.89 6.04 3.71 0.27 37.15

The Lemna biomass is a light fluffy solid with a density of about 490 kg / m ³ . It can be pelletized for transport to the refinery to minimize hygroscopic water absorption, providing ease of treatment with minimal dusting. The biomass contains lipids, carbohydrates, protein residues, cellulose, and other organic materials of little or no interest to a typical petroleum refinery, with the exception of the potential to convert them to hydrocarbons and particularly valuable liquid transport fuels or chemical intermediates.

Hydrocarbons derived from mineral sources are mainly composed of organic compounds such as carbon and hydrogen, with varying amounts of sulfur-containing and nitrogen-containing molecules and very low levels of oxygen, generally less than 0.5%, and metals. The above biomass test shows very little sulfur, lots of nitrogen and metals plus a very high oxygen content, compared to typical lagoon raw oil for a delayed coker. The biomass carbon to hydrogen weight ratio (C: H) is 7.6 but is only 52% by weight of the total. In comparison, a typical heavy oil residue fed to a commercial delayed coker could have a hydrogen content of 8.5 to 11 wt% with a C: H ratio of the order of 8.5 to 9.0. This ratio varies significantly by raw derivatization and residue processing upstream of the delayed coker. By inspection, it can be expected that the yield of liquid hydrocarbons from the biomass to be converted in a delayed coker will be lower than that obtained from conventional residual starting materials. In addition, the conversion of complex biological organic solid components into non-condensable gases, liquids and coke (coal) in a delayed coker would be unique and the reactions more complex than those encountered in conventional coking of liquid petroleum residues, even complex residues.

example 1

The Lemna biomass residue was co-processed following protein extraction with various petroleum residues in a delayed pilot coke plant to provide evidence of the principle of biomass conversion to liquids useful in a petroleum refinery and to provide information on it how the reactions differ from conventional coking. This work was carried out in several runs, each involving the processing of petroleum standard residues obtained in the base operation from a commercial refinery. In further runs, the lemna biomass was mixed with the residue in varying proportions that the pilot plant apparatus could handle, and the resulting slurry was coked. Each run series was made with a fixed baseline residue, which was also the slurried liquid vehicle. To maximize liquid yields, each run was performed at low pressure of 15 psig and zero recycle, i. H. without recycling. The feeds and products were analyzed. The results were reviewed and analyzed, and the net yield structure from the biomass was determined by difference.

Slurry concentrations of 10 and 20 wt% biomass in petroleum residue were tested. This was the limit of pilot plant capacity. However, in a commercial unit, depending on the capacity of the unit, higher concentrations up to 40 or 50 wt% or more are possible.

Table 2 below shows the results of coking Lemna biomass as a 10% mixture with a slight vacuum residue. Table 2 Yield and elemental composition of Lemna biomass coking products Wt .-% Metals & Minerals C H N S O total gas 24,66 0.00 28.22 0.00 0.00 0.00 71.78 100.00 CO ₂ , solved 0.51 0.00 27.27 0.00 0.00 0.00 72.73 100.00 NH ₃ 3.41 0.00 0.00 17.65 82.35 0.00 0.00 100.00 Reaction H ₂ O 17.34 0.00 0.00 11.11 0.00 0.00 88.89 100.00 H ₂ S 0.05 0.00 0.00 5.88 0.00 94.12 0.00 100.00 liquid product 31.83 Minimal 84.67 8.12 0.77 0.44 6.08 100.08 coke 22.20 16.79 63.60 2.45 3.56 0.43 13.19 100.02 total 100.00 3.73 48.17 5.66 3.85 0.28 38.35 100.03 biomass test 3.60 47,54 6.26 3.85 0.28 38.49 100.00 error 3.6% 1.3% -9.5% 0.0% 0.5% -0.4%

The results on varying series and with different vacuum residues processed were similar. The variation in total is due to (1) "noise" in yield, recovery and differential analysis; (2) Reproducibility and repeatability of feed product testing and (3) smaller data fining trials by the researchers.

The lemna biomass mixes well with the petroleum vacuum residue. The biomass has an average particle size of about 100 to about 150 microns, and the bulk density is about 490 kg / m ³ . When the biomass is pelletized to provide a less polluting, safer and more convenient transport, crushing and milling are used to produce the small particles for testing. The mixing is improved by milling into smaller particles, about 50 microns on average.

The principle of solid biomass degradation by coking to gas, liquid products and coke is effectively demonstrated, i. H. the principle is proved. In particular, liquid products for further processing in a petroleum refinery are produced in considerable quantities.

In one embodiment of the invention, the gas produced is almost only CO ₂ , with minor amounts of hydrogen and light hydrocarbons (methane, ethane, ethene, etc.).

In one embodiment of the invention, a high percentage of light gas is produced, over 20%, compared to the typical 8 to 10% that are common when pure petroleum residues are coked. A high percentage of the biomass nitrogen content reacts to form ammonia.

It turns out that the relatively high oxygen content of the biomass relative to delayed petroleum coke feed reacts mainly to gas as CO ₂ and water with a relatively high amount of oxygen in the coke. The liquid product has a high amount of oxygen relative to liquid product produced from a petroleum residue coking feed. However, the value is low compared to the total biomass oxygen content, and when diluting in operation with the liquid produced from the petroleum residue, the degradation of other refinery processes, such as hydrogenation, is mitigated.

reactions

The oxygen reacts with coke-forming components in the feed and gives cokes of higher oxygen content and makes the coke more isotropic. This finding could be used by admixing limited, low biomass data to enhance the isotropic nature which affects the friability and hardness of anode specialty coke. While testing blends of 10 wt.% And 20 wt.% Biomass in petroleum residue, we were able to significantly influence the physical coke structure. Coke produced without any biomass in the feed has a sponge structure that is associated with good anode coke when using a petroleum residue known for producing anodic coke. The coke produced with 10% and 20% biomass in the feed mixture was very dense and showed low porosity, consistent with highly isotropic shot coke structure. This phenomenon is explained by the high content of released oxygen compounds in the biomass, which react with the coke-forming materials in the bioteids and in the petroleum residue.

Although the present invention has been described in its preferred embodiment and with representative examples, herein the basic concept to which the present invention is based is a method of producing biofuels from co-processing of biomass together with hydrocarbon feedstock in a delayed coker unit A way in which a person skilled in the art would be able to practice variations, modifications, changes, adaptations and substitutions that are consistent with the subject matter discussed and yet depart from the spirit and scope of the present invention as set out in the appended claims.

Claims (22)

Process for the production of biofuels by co-processing of biomass in a refinery heat processing unit, comprising the following steps: Feeding a supply material into a heat processing unit; wherein the feed comprises a mixture of hydrocarbons and a solid biomass material; Heat processing the feed material; and Collecting the reaction products generated from the heat processing of the feedstock. The method of claim 1, wherein the solid biomass material is from a vegetable source, an animal source or an aquatic source. The method of claim 2, wherein the aquatic source is an aquatic plant. The method of claim 3, wherein the aquatic plant is Lemna or comes as a solid residue from Lemna after protein extraction. The process of claim 1 wherein the hydrocarbons in the feed are petroleum residues and distillates. The method of claim 1, wherein the solid biomass material is present in a concentration of 10 to 20% by weight. The method of claim 1, wherein the solid biomass material is present in a concentration of 40 to 50% by weight. The method of claim 1, wherein the solid biomass material is present in a concentration of 0.1 to 60% by weight. The method of claim 1, wherein the heat processing unit is a delayed coker. The process of claim 1, wherein the reaction products comprise carbon dioxide, ammonia and acetic acid. The method of claim 4, wherein the lemna is preprocessed to remove protein before it is introduced into the feed. The method of claim 1, wherein the feed material is supplied to a coker fractionator. The method of claim 1, wherein the feed material is supplied directly to the coke drum. The method of claim 1, wherein the feed material is supplied directly to a heating supply line. The method of claim 1, wherein the feed is heated before being fed to the heat processing unit. The method of claim 1, wherein the heating process is a delayed coking process. The method of claim 1, wherein the heating process is a fluidized bed coking process. The process of claim 14, wherein the coking process is a delayed coking process, wherein the feed stream is heated at a pressure of 300 to 4000 kPa to a temperature of 460 ° C to 530 ° C, after which the heated stream is at a pressure of 65 to 1100 kPa and a temperature of 400 to 475 ° C is discharged into a delayed coke drum. The process of claim 15, wherein the coking process is a fluidized bed coking process wherein the feed stream is discharged at a pressure of from atmospheric to 400 kPa at a temperature of from 480 ° C to 565 ° C in a fluidized bed coking reactor. Process for the preparation of isotropic coke, comprising the following steps: a) combining a feedstock comprising a mixture of hydrocarbons and a solid biomass material, and b) Performing a heat process with the combined material to produce an isotropic coke. The method of claim 18, wherein the isotropic coke exhibits low porosity. The method of claim 18, wherein the solid biomass material is present in the feed at 0.1% to 60% by weight.

Images